The employment of one of these objects causes everyone around, including its user, to weep, after which its user promises a beautiful plumage to any bird that can gather his tears from the waters, a task accomplished by the duck. Another instance of this object's use causes warriors to lay down their arms, but that object is lost when the warship on which its owner is sailing is buffeted by winds and waves sweep this object overboard. After losing the first of these objects, its owner commissions an iron rake to look for it at the bottom of the sea, but after failing to find it, creates a second one of these objects from birchwood, using the hair of a virgin for strings.  That second example of this object is left behind after its original owner departs in a copper boat, while the first example of this object is m
The employment of one of these objects causes everyone around, including its user, to weep, after which its user promises a beautiful plumage to any bird that can gather his tears from the waters, a task accomplished by the duck. Another instance of this object's use causes warriors to lay down their arms, but that object is lost when the warship on which its owner is sailing is buffeted by winds and waves sweep this object overboard. After losing the first of these objects, its owner commissions an iron rake to look for it at the bottom of the sea, but after failing to find it, creates a second one of these objects from birchwood, using the hair of a virgin for strings.  That second example of this object is left behind after its original owner departs in a copper boat, while the first example of this object is made from the jawbone of a pike, and not even Lemminkainen can make good music from it. For ten points, identify this harp-like or zither-like instrument of Finnish folklore, employed by Vainamoinen in the Kalevala.
The employment of one of these objects causes everyone around, including its user, to weep, after which its user promises a beautiful plumage to any bird that can gather his tears from the waters, a task accomplished by the duck.
{kantele} [accept {Vainamoinen's harp} or {Vainamoinen's zither} before mention of that answer part, {i.e. you can} accept {Vainamoinen's harp} after “{harp}” {has been} mentioned but before “{Vainamoinen}”; prompt on partial answers]